Breaking mill



Dec. 18, 1962 w. PALLMANN BREAKING MILL 2 Sheets-Sheet 1 Filed Aug. 1, 1960 FIG.

INVENTOR. Z/M Kala PoZZMM Dec. 18, 1962 Filed Aug. 1, 1960 FIG. 2

W. PA LLM AN N BREAKING MILL 2 Sheets-Sheet 2 INVEN OR. 411-5444 mm United States Patent Ofilice 3,069,103 Patented Dec. 18, 1962 3,069,103 BREAKING MILL Wilhelm Pallmann, Zweibrucken, Pfalz, Germany, assignor to Ludwig Pallrnann Maschinenfabrik und Mahlwerk KG., Zweibrucken, Pfalz, Germany Filed Aug. 1, 1960, Ser. No. 46,732 Claims priority, application Germany Aug. 1, 1959 12 Claims. (Cl. 241-251) The present invention relates to a breaking mill, and more particularly to a breaking mill of the type in which a rotor subjects a material to centrifugal action to move the material in outward direction against a breaking surface.

In known breaking mills of this type the material is supplied to a central region of the rotor, and moves outwardly under the action of centrifugal force so that the exact distribution of the material along the breaking surface cannot be determined.

It is one object of the present invention to improve known breaking mills of this type and to provide a breaking mill in which the material is uniformly distributed along the entire breaking surface, or surfaces.

Another object of the present invention is to guide the material to axially spaced portions of the breaking surface, so that the material is more uniformly distributed along the breaking surface.

A further object of the present invention is to guide the material to axially spaced portions of alternately circumferential adjacent portions of the breaking surface, or surfaces.

A further object of the present invention is to provide a breaking gap between a rotor surface, and two outer breaking surfaces which define an outlet between each other, and to guide material to opposite axially spaced sides of the gap so that it is uniformly distributed along the breaking surfaces.

Another object of the present invention is to reduce the heat developed in broken-up material by more uniformly distributing the material over breaking surfaces.

A further object of the present invention is to improve the efficiency of known breaking mills by more uniformly distributing the material along the breaking surfaces of the mill.

With the above objects in view, the present invention mainly consists in a breaking mill which comprises a means having a first annular breaking portion; a .rotor having a second annular breaking portion confronting the first annular breaking portion and defining a crushing gap with the same, and means for supplying a material to the central portions of the rotor so that the supplied material moves outwardly under the action of the centrifugal force toward the gap between the breaking portions. In accordance with the present invention, the rotor includes guide means extending from the central portions thereof outwardly to axially spaced portions of the breaking portions and of the gap between the same whereby the material enters the gap at axially spaced points thereof and is uniformly distributed between the breaking portions during the crushing operation.

In the preferred embodiment of the present invention the rotor has a cavity which is divided into sector-shaped spaces by radially extending walls. Some spaces are partly closed on one side of the rotor by walls extending inwardly from the breaking portion and defining central openings at one side of the rotor. The other side of the rotor is almost completely closed by a circular wall. Selected chambers are closed by guide walls at the supply side of the rotor, while other guide walls extend obliquely through the rotor, and guide the material to the other side of the rotor. In this manner, the material is alternately supplied to axially spaced parts of the breaking surfaces located on opposite sides of the rotor, and is consequently very well distributed during the breaking-up operation.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIG. 1 is a side elevation, partly in section, illustrating a breaking mill according to the present invention;

FIG. 2 is a front view of the rotor of the breaking mill as viewed in the direction of arrow 2 in FIG. 1; and

FIG. 3 is a rear view of the rotor.

Referring now to the drawing, a pulley 1 is driven by a suitable motor, not shown, and rotates the hollow shaft 2 secured thereto. The free end of shaft 2 carries a breaking member 3 which has a breaking portion 4 of general frusto-conical shape on the inner side of which breaking plates 5 are exchangeably mounted. Breaking plates 5 have rough surfaces so that the breaking portions 4- may be considered to have a rough frusto-conical breaking surface.

A shaft 7 is located within the hollow shaft 2, and supported therein by a hearing. The left end of shaft 7 is secured to a pulley 6 and driven through the same in the direction of rotation opposite to the direction of rotation of the hollow shaft 2. A rotor R is secured to the free end of shaft 7 and includes a hub portion, and a circular wall 8 on one side. A plurality of evenly spaced radial walls 9 extend from the hub portion to a pair of breaking portions 13 and 13' each of which is of frusto-conical shape and has an outer frusto-conical breaking surface, the breaking surfaces facing in opposite directions. The breaking surface of the breaking portion 13 confronts the breaking surface of the breaking portion 4 with the breaking plates 5, and forms a crushing gap 5a with the same.

The peripheral circular edge of the circular wall 8 defines a circular gap with one edge of breaking portion 13.

Radial walls 9, the circular wall 8, and the breaking portions 13, 13 form radially extending sector-shaped spaces in the rotor. Alternate spaces are closed by Wall 8 and walls 14 extending between the edge of breaking member 13 and the hub of the rotor so that closed chambers 16 are formed in the rotor between selected Walls: 9, which slightly project from wall portions 14.

Other wall portions 29 of smaller radial extension are located between edges of other selected pairs of radial walls 9. Guide walls 15 extend from the inner edges of wall portions 20 to the respective portion of the annular edge of the breaking portion 13', so that the closed chambers 17 are formed in the outer part of the rotor which alternate in circumferential direction with the chambers 16. Walls 15 and peripheral portions of Wall 8 form gaps 8a located along the circular outer edge of wall 8.

A chute 21 is located opposite the central portion of of the rotor, so that material supplied thereto will fall through the rotor along the guide surfaces of guide walls 15, as indicated by arrow 13c, and through the gaps 8a between wall 8 and breaking portion 13, or will fall against the outer guiding surface of the wall portion 14 and remain on the respective side of the rotor, as indicated by arrows 13c and 13d.

The breaking member 3 is located in a housing 10 which carries another breaking member 11 having a breaking portion with a frusto-oonical breaking surface 5' constructed similar to the breaking surface 5 of the rotary breaking member 3. Breaking member 11 is stationary, but adjustable in axial direction of the rotor, so that the width of the outlet opening 12 between the breaking surfaces 5 and 5' can be adjusted. Brackets 11a are secured to member 11. A nut means 11b is carried by each bracket 11a and threadedly engages a threaded spindle 22 which is turnable in a bearing portion 16a of a ring-shaped housing part b. Turning of spindles 22 will cause axial movement of nut means 11b and axial adjustment of breaking member 11. Breaking surface 5 confronts the breaking surface of the breaking portion 13, so that the breaking surfaces 5, 5 form with the breaking surfaces 13, 13', a crushing gap 5a, 1301 which has the outlet opening 12 at the center thereof.

The width of the gap 13a and of outlet opening 12 can be adjusted by adjustment of the position of breaking member 11 by means of spindles 22 and nut means 11b.

The breaking mill operates in the following manner:

Pulleys 6 and 1 are rotated in opposite directions, so that the breaking member 3 and the breaking portion 5' rotate in one direction and the rotor R rotates in an opposite direction. Breaking surface 5' is stationary.

Material to be broken up is supplied through chute 21 and falls against one side of the rotating rotor. Some material will drop against the guide surfaces of the guide walls 14 as indicated by arrow 13c and be guided in outward direction along the same between ridges formed by the edges of the respective walls 9, as indicated by arrow 13d, while being moved by the centrifugal force until the material enters into gap 13a through an inlet opening 13b formed between the edges of the breaking surfaces 13 and breaking surface 5. The material travels through the gap 130 toward the outlet 12, is crushed between surfaces 5' and 13', and is broken up to pass through outlet 12 into the interior of the housing 10 from which it is guided through a discharge opening 23.

However, not all the material travels this: path, but since every second pair of walls 9 is provided with guide means 15, about half of the material will be guided by the guide surfaces of walls 15 to the other side of the rotor, as indicated by arrow 13e, where the material will be confined by wall 8 and will pass along a circular line formed by the moving gaps 8a, through gaps 8a, and through the circular gap between the outer peripheral edge of wall 8, and the outer edges of wall portions 15. This part of the material will enter through the circular inlet opening 512 on the other side of the rotor into gaps 5a between breaking surfaces 5 and 13 where it is crushed while traveling outwardly along the breaking surfaces until it reaches the outlet opening 12.

Since the material is uniformly supplied to axially spaced points of the gaps between the breaking surfaces, and moreover is supplied to circumferentially spaced portions of the breaking surfaces, the distribution of the material is very uniform, and the efiiciency of the mill is substantially increased as compared with known constructions.

As shown in FIGS. 2 and 3, every second space between Walls 9 has a guide wall 15 for guiding the material, to the other side of the rotor.

Since due to the better distribution of the material along the breaking surfaces the heat developed in the broken up material and in the machine is substantially reduced and as compared with conventional breaking mills, synthetic materials, such as polyethylene, Plexiglas, etc., can be broken up by the machine of the present invention, although these materials are very sensitive to overheating.

It will be understood that each of the elements described above or two or more together, may also find a useful application in other types of breaking mills differing from the types described above.

While the invention has been illustrated and described as embodied in a breaking mill with a rotor formed with guide channels for guiding the material to axially spaced points of a breaking surface, it is not intended to be limited A to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Such modifications should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed and desired to be secured by Letters Patent is:

1. In a breaking mill, in combination, a means having a first annular breaking portion including two frustoconical axially spaced breaking surfaces confronting each other and defining a circular outlet opening between each other; a rotor rotatable about an axis and having a second annular peripheral breaking portion including two oppositely facing, frusto-conical breaking surfaces confronting said first annular breaking surfaces and defining a gap with the same, said rotor including guide channel means extending from central portions thereof to circumferentially spaced portions of said second peripheral breaking portion and of said gap, some of said portions being spaced from other portions also in the direction of said axis; and means for supplying a material to said central portions of said rotor so that the supplied material moving outwardly under the action of the centrifugal force along said guide means is uniformly distributed in said gap.

2. In a breaking mill, in combination, a rotary member having an axis of rotation and a first annular breaking portion extending at an angle to and facing said axis of rotation; a rotor rotatable about said axis in opposite sense to said rotary member and having a second annular breaking portion extending at said angle to said axis and confront-ing said first annular breaking portion and defining a gap with the same, said rotor including a hub, and walls extending in radial direction between said hub and said second annular breaking portion to form circumferentially adjacent sector-shaped spaces within said rotor, said rotor including guide wall means extending in said spaces and forming guide surfaces and closed chamber portions in the same, said guide surfaces extending from central portions of said rotor outwardly to portions of said second peripheral breaking portion and of said gap; and means for supplying a material to said central portion of said rotor so that the supplied material moving outwardly under the action of the centrifugal force along said guide surfaces enters said gap at and circumferentially spaced points thereof and is uniformly distributed in said gap between said first and second breaking portions to be crushed between the same.

3. In a breaking mill, in combination, a rotary member having an axis of rotation and a first annular breaking portion extending at an angle to and facing said axis of rotation; a rotor rotatable about said axis in opposite sense to said rotary member and having a second annular breaking portion extending at said angle to said axis and confronting said first annular breaking portion and defining a gap with the same, said rotor including a hub, and walls extending in radial direction between said hub and said second annular breaking portion to form circumferentially adjacent sector-shaped spaces within said rotor, said rotor including guide wall means extending in said spaces and forming guide surfaces and closed chamber portions in the same, said guide surfaces extending from central portions of said rotor outwardly to circumferentially spaced portions of said second peripheral breaking portion and of said gap; and means for supplying a material to said central portion of said rotor so that the supplied material moving outwardly under the action of the centrifugal force along said guide surfaces is uniformly distributed in said gap between said first and second breaking portions to be crushed between the same.

4. In a breaking mill, in combination, a rotary member having an axis of rotation and a first annular breaking portion extending at an angle to and facing said axis of rotation; a rotor rotatable about said axis in opposite sense to said rotary member and having a second annular breaking portion extending at said angle to said axis and confronting said first annular breaking portion and defining a gap with the same, said rotor including a hub, and walls extending in radial direction between said hub and said second annular breaking portion to form circumferentially adjacent sector-shaped spaces within said rotor, said rotor having first guide wall means extending through said spaces and having guide surfaces leading from central portions of said rotor on one side of the same to circumferentially spaced portions of said gap located on the second side of said rotor, and other guide wall means closing said chambers on said one side of said rotor and having guide surfaces leading from central portions of said rotor to other circumferentially spaced portions of said gap located on said one side of said rotor; and means for supplying a material to said central portions of said rotor from said one side so that the supplied material is guided by said guide surfaces to move outwardly under the action of the centrifugal force and enters said gap at axially and circumferentially spaced points thereof and is uniformly distributed in said gap.

5. In a breaking mill, in combination, a stationary housing; a first breaking member mounted in said housing for rotation about an axis and having a first frustoconical breaking portion concentric with said axis of rotation and facing toward the same; a second breaking member mounted on said housing and having a second frustoconical breaking portion concentric with said axis of rotation and facing toward the. same, said frusto-conical breaking portions confronting each other and being axially spaced from each other to define a circular outlet opening between said first and second breaking portions; a rotor rotatable about said axis and having an annular breaking portion including two oppositely facing frusto-conical breaking portions located inwardly of said first and second breaking portions and respectively confronting the same to form an annular gap with the same having circular axially spaced inlet openings spaced a smaller radial distance from said axis than said outlet opening and located on opposite sides of the same, said rotor including guide means extending from central portions thereof in a selected order alternately to said inlet openings; and means for supplying a material to said central portions of said rotor so that the supp-lied material moving outwardly under the action of the centrifugal force along said guide means enters said gap through both said inlet openings and is uniformly distributed in the gap portions between said inlet openings, respectively, and said outlet opening.

6. In a breaking mill, in combination, a stationary housing; a first breaking member mounted in said housing for rotation about an axis and having a first frusto-conical breaking portion concentric with said axis of rotation and facing toward the same; a second breaking member mounted on said housing and having a second frustoconical breaking portion concentric with said axis of rotation and facing toward the same, said frusto-conical breaking portions confronting each other and being axially spaced from each other to define a circular outlet opening between said first and second breaking portions; a rotor rotatable about said axis and having an annular breaking portion including two oppositely facing frusto-conical breaking portions located inwardly of said first and second breaking portions and respectively confronting the same to form an annular gap with the same having circular axially spaced inlet openings having smaller diameters than the diameter of said outlet openings and located on opposite sides of the same, said rotor having radial walls extending from the center of said rotor to said breaking portions, wall portions inwardly projecting from one of said breaking portions and from one of said inlet openings on one side of said rotor between first selected pairs of said radial walls, a circular wall on the other side of said rotor extending outwardly from the center of said rotor and having a circular peripheral edge defining with the other'breaking portion of said rotor gaps located in the region of the other inlet opening between second selected pairs of said radial walls, first guide walls extending from the inner edges of said wall portions between said first selected pairs of said radial walls to said gaps, respectively and to circumferentially spaced portions of said other inlet opening, second guide walls extending on said one side of said rotor from the center portion thereof to said one breaking portion along the edges of said second selected pairs of said radial Walls and having guide surfaces on said one side of said rotor leading to other circumferentially spaced portions of said one inlet opening; and means for supplying a material from said one side of said rotor to the center region within said wall portions so that said first guide walls and said circular wall guide the material to the inlet opening on the other side of said rotor and said second guide walls guide the material to the inlet opening at said one side of said rotor so that the material is uniformly distributed in the gap portions between said inlet openings and said outlet opening.

7 A breaking mill as set forth in claim 6 wherein said first guide walls alternate with said second guide walls in circumferential direction of said rotor.

8. In a breaking mill, in combination, a means havin; a first annular breaking portion; a rotor rotatable about an axis and having a second annular breaking portion confronting said first annular breaking portion and defining an annular crushing gap with the same, said rotor having radial walls extending from the center of said rotor to said breaking portion, wall portions on one side of said rotor inwardly projecting from said breaking por tion between first selected pairs of radial walls, a circular wall on the other side of said rotor extending outwardly from the center of said rotor and having a circular peripheral edge defining with said breaking portion of said rotor gaps located on the other side of said rotor, first guide walls extending from the inner edges of said wall portions between said first selected pairs of said radial walls to said gaps, respectively, and to circumferentially spaced portions of said gap, second guide walls extend ing on said one side of said rotor from the center portion thereof to said breaking portion along the edges of said second selected pairs of said radifl walls and having guide surfaces on said one side of said rotor leading to other circumferentially spaced portions of said annular crushing gap; and means for supplying a material from said one side of said rotor to the center region within said wall portions so that said first guide walls and said circular wall guide the material to the other side of said rotor and said second guide walls guide the material at said one side of said rotor so that the material is uniformly distributed in the gap bet-ween said first and second breaking portions to be crushed between the same.

9. A breaking mill as set forth in claim 8 wherein said first guide walls alternate with said second guide Walls in circumferential direction of said rotor.

10. A breaking mill as set forth in claim 5 wherein said second breaking member is mounted on said housing movable in axial direction of said rotor for adjustment of said gap and of said outlet opening.

l1. A breaking mill as set forth in claim 6 wherein said second breaking member is mounted on said housing movable in axial direction of said rotor for adjustment of said gap and of said outlet opening.

12. In a breaking mill, in combination, a stationary housing; a first breaking member mounted in said housing for rotation about an axis and having a first frustoconical breaking portion concentric with said axis of rotation and facing toward the same; a second breaking member mounted on said housing and having a second frustoconical breaking portion concentric with said axis of rotation and facing toward the same, said frusto-conical breaking portions confronting each other and being axially spaced from each other to define a circular outlet opening between said first and second breaking portions; a rotor rotatable about said axis and having an annular breaking portion including two oppositely facing frustoconical breaking portions located inwardly of said first and second breaking portions and respectively confront' ing the same to form an annular gap with the same having circular axially spaced inlet openings spaced a smaller radial distance from said axis than said outlet opening and located on opposite sides of the same, said rotor including a hub, and walls extending in radial direction between said hub and said second annular breaking portion to form circumferentially adjacent sector-shaped spaces within said rotor, first guide wall means extending between pairs of said radially extending walls through selected spaces and having guide surfaces leading from central portions of said rotor on one side of the same to the inlet spacing located on the other side of said rotor, and second guide wall means extending between other pairs of said radially extending walls in other spaces on said one side of said rotor and having guide surfaces leading from central portions of said rotor to the inlet References Cited in the file of this patent UNITED STATES PATENTS 20,370 Rand May 25, 1858 990,633 Campbell Apr. 25, 1911 1,772,150 Knowles Aug. 5, 1930 2,750,120 Pallmann June 12, 1956 2,778,282 Sutherland Jan. 22, 1957 2,937,815 Eirich May 24, 1960 FOREIGN PATENTS 1,026,159 Germany Mar. 13, 1958 n -nae 

